1. Field of the Invention
The present invention relates to a sliding part and a method for producing the same, said sliding part consisting of a shaft and a bearing, the former fitting into the latter, such as a combination of a journal and a journal bearing and a combination of a spline shaft (internal spline) and a hub (external spline). More particularly, the present invention relates to a sliding part in which a resin lining is formed on the bearing surface of the bearing by monomer casting, and it also relates to a method for producing the sliding part.
2. Description of the Prior Art
Sliding parts with a resin lining have been in general use in automobiles and many other machines. The conventional sliding parts fall under two broad categories: (A) There are sliding parts constructed of a shaft, a bearing and a bushing interposed between them, said bushing being formed by coating a flat, metal plate with a resin, cutting the coated plate to proper size, curling the cut plate, and fitting the curled plate into the bearing surface of the bearing, as in the case of a Teflon resin-coated bushing. (B) There are sliding parts constructed of a bearing with the bearing surface thereof directly coated with a resin and a shaft machined to fit into the bearing.
The sliding parts belonging to category (A) have the following disadvantages: (1) Both the lining and the shaft should have a considerably high dimensional accuracy, which sometimes needs the selective fitting of accurately matching parts. (2) Depending on the shape of the bearing surface, it may be difficult to fit the lining. (3) The production cost of the lining is high. On the other hand, the sliding parts belonging to category (B) have the following disadvantages. (1) The machining of the shaft is indispensable, which adds to the cost of the sliding part. (2) The machining of the shaft should be performed with high accuracy and selective fitting may be necessary in some instances.